At least 78 people were killed in a suicide bomb attack outside a church in the Pakistani city of Peshawar.
The attack is one of the deadliest on Christians in the predominantly Muslim country.
Explosions struck the All Saints Church as hundreds of parishioners, many of them women and children, streamed out of the building.
Interior Minister Chaudhry Nisar Ali Khan said 34 women and seven children were among the dead. Over 100 people were injured.
Violence has been on the rise in Pakistan, undermining Prime Minister Nawaz Sharif's efforts to launch peace talks with the Pakistani Taliban.
The Taliban-linked militant group TTP Jundullah claimed responsibility within hours of the attack.
A bomb disposal security source said there were two explosions carried out by a pair of attackers.
Christians make up about 4% of Pakistan's population of 180m.
Some residents, enraged at the lack of adequate security at the church, took to the streets after the attack, burning tyres and shouting slogans.
Shops were closed in the Kohati Gate area where several other churches are located.
Protests by Christians were also reported in other cities including Karachi and Multan.
Pope Francis condemned the suicide bombing as an act of "hatred and war".
"Today, in Pakistan, because of a wrong choice, a decision of hatred, of war, there was an attack in which 70 people died."
He said: "This choice cannot stand. It serves nothing. Only the path of peace can build a better world."
Attacks on Christian areas occur sporadically around Pakistan but the assault in Peshawar was the most violent in recent history.
In 2009, 40 houses and a church were set ablaze by a mob of 1,000 Muslims in the town of Gojra in Punjab province. At least seven Christians were burnt to death.
Seventeen Christians were killed in an attack on a church in Bahawalpur in 2001.